Oxirane Ethylene Oxide

It is often the case that chemists involved or familiar with ethylene oxide (oxiran) chemistry refer to these cyclic oligomers as EO-4, EO-6 and EO-7 respectively. Such designations are informal if not colloquial but, like any name, are useful if they correctly convey an idea. The difficulty with these informalities, indeed with the crown nomenclature system is that it cannot adequately deal with complicated structures or even isomers of simple ones. 

Dihydro-2f/-pyran-2-one has been prepared by reductive cycliza-tion of 5-hydroxy-2-pentynoic acid [2-Pentynoic acid, 5-hydroxy-], which is obtained in two steps from acetylene [Ethyne] and ethylene oxide [Oxirane] 3 and by the reaction of dihydropyran [277-Pyran, 3,4-dihydro-] with singlet oxygen [Oxygen, singlet].4,5 2ff-Pyran-2-one has been prepared by pyrolysis of heavy metal salts of coumalic acid [2//-Pyran-5-carboxylic acid, 2-oxo-],8 by pyrolysis of a-pyrone-6-carboxylic acid [211 - Pyran-6-carboxyl ic acid, 2-oxo-] over copper,7 and by pyrolysis of coumalic acid over copper (66-70% yield).8... 

Hydroxyethyl cellulose, three samples prepared from alkali cellulose and ethylene oxide (oxirane) to low degrees of molar substitution (MS) about 0.25, 0.4 and 0.6 moles of oxirane substituted per mole of glucose units (some oxirane units form substituted oligo-ethylene glycol chains). 

N-Alkylation with Ethylene Oxides (Oxiranes) or Aziridines... 

Ethylene oxides (oxiranes) react exothermally at room temperature with ammonia and most strongly basic amines presence of water or an alcohol accelerates the reaction. N.B. There is danger of explosions when working with oxirane. 

Strained cyclic ethers react with aromatic compounds with formation of hydroxyalkyl derivatives with ethylene oxide (oxirane) and aluminum chloride, benzene gives phenethyl alcohol in 70% yield,541 and with oxetane gives... 

The conversion of epoxides into carbonyl compounds is an irreversible reaction. At 400° ethylene oxide (oxirane) passes into acetaldehyde, and at 500° propylene oxide (1-methyloxirane) gives a 2 1 mixture of propion-... 

Ethylene glycol is obtained commercially by addition of water to ethylene oxide (oxirane). Its most important impurities are propylene glycol and di-and tri-ethylene glycol, which, however, are rarely detrimental to its use as a solvent. It is extremely hygroscopic and thus almost always contains water. For purification and removal of water it is dried over sodium sulfate12 and then fractionated in a vacuum but it may also be distilled in a vacuum without pre-drying — the water passes over in a forerun since the glycol does not form an azeotrope with water. 

Dihydro-2//-pyran-2-one has been prepared by reductive cycliza-tion of 5-hydroxy-2-pentynoic acid [2-Pentynoic acid, 5-hydroxy-], which is obtained in two steps from acetylene [Ethyne] and ethylene oxide [Oxirane] and by the reaction of dihydropyran [2Jf-Pyran,... 

Ethylene oxide (oxirane) Trimethylene oxide (oxetane) Tetrahydrofuran (oxolane) Tetrahydropyran (oxane)... 

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